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Methods to measure protein, exopolysaccharide, viable cell number and INT reduction activity were tested on biofilm growing in a wastewater batch reactor. They were shown to be meaningful indicators of biofilm growth and correlated well with each other. Protein, exopolysaccharide, viable cells and INT reduction rates increased linearly over time. Viable cell number exhibited strong linear correlations with protein (R2=0.98) and exopolysaccharide (R2=0.99) while INT reduction rate was somewhat less well correlated (R2=0.90). Our results indicate production rates of 0.91×10-7 μg EPS per viable cell and 1.0×10-7 μg protein per viable cell.Protein and polysaccharide specific INT reduction rates decreased by approximately 50%, whereas viable cell specific INT reduction rates decreased by 65% and the protein to polysaccharide ratio stayed relatively constant at between 1.1 and 1.2 as the biofilm developed.Measurement of protein, polysaccharide, viable cells and INT reduction rate at depth within the bioreactor showed that they were concentrated in the top 1 cm of the influent end of the reactor and each decreased to a base level within 4.5 cm of the inlet. Protein to polysaccharide ratios increased with depth in the reactor and the specific INT reduction rates were maximal at 4.5 cm depth.The results indicate that the biomass can take upwards of 100 days to stabilize during batch (fill and draw) operation of subsurface wetlands and that the relative ratios of biomass components remain relatively constant during biofilm growth. Also, it appears that filtration of suspended solids results in biomass concentration at the inlet to the wetland. [Copyright &y& Elsevier]

Inhibition of the kynurenine pathway of tryptophan metabolism during gestation can lead to changes in synaptic transmission, neuronal morphology and plasticity in the rat hippocampus. This suggests a role for the kynurenine pathway in early brain development, probably caused by kynurenine modulation of N-methyl-d-aspartate (NMDA) glutamate receptors which are activated by the tryptophan metabolite quinolinic acid and blocked by kynurenic acid. We have now examined samples of neocortex and cerebellum of adult animals to assess the effects of a prenatally administered kynurenine-3-monoxygenase inhibitor (Ro61-8048) on protein and mRNA expression, dendritic structure and immuno-histochemistry. No changes were seen in mRNA expression using quantitative real-time polymerase chain reaction. Changes were detected in the expression of several proteins including the GluN2A subunit, unco-ordinated-5H3 (unc5H3), doublecortin, cyclo-oxygenase, sonic hedgehog and Disrupted in schizophrenia-1 (DISC1), although no differences in immunoreactive cell numbers were observed. In the midbrain, dependence receptor expression was also changed. The numbers and lengths of individual dendritic regions were not changed but there were significant increases in the overall complexity values of apical and basal dendritic trees. The data support the hypothesis that constitutive kynurenine metabolism plays a critical role in early, embryonic brain development, although fewer effects are produced in the neocortex and cerebellum than in the hippocampus and the nature of the changes seen are qualitatively different. The significant changes in DISC1 and unc5H3 may be relevant to cerebellar dysfunction and schizophrenia respectively, in which these proteins have been previously implicated. [ABSTRACT FROM AUTHOR]